definitely go road frame-- you'll love it. THe 'standard' gearing for a fixie starts at 3x1. In other words, if you have a 48 tooth chainring, use a 16 tooth cog. If you have a 42 tooth chainring, use a 14 tooth cog. That's a good starting point. Try it and see how it does. Realize that you will be able to climb in a higher gear on a fixie than you would on a road bike.

My personal experience was to start with a 48x18, whch I could do almost everything around here (Washinton DC area), but I found I wasn't spinning. I was limiting myself to around 80 rpm. I changed the rear cog to an 18 tooth, and now I spin much better. I also haven't hit a hill I couldn't climb in it (knock on wood). I did a hilly century on it last year, and came really close to walking, but made it up--it wasn't pretty, but I didn't walk.

Keep the front brake-- you will use it to slow down on the downhills. You can stop without it, but it will be taxing on your knees. And once those go, it's hard to get a replacement

At any rate, enjoy the challenge (it will take a few rides to get the hang of it--and to remember not to coast-- the bike reminds you really quickly).

train safe-